This invention relates to a winding machine, and more particularly to a winding machine for simultaneously winding strips, which are offset relative to each other and have been slit lengthwise from a web, onto at least two winding rolls.
A winding machine of this type is disclosed in DE-OS No. 20 15 722, wherein the three supporting rollers are arranged one above the other. One winding bed extends on one side of this roller arrangement and a second winding bed extends on the other side. In this disclosed winding machine, the total weight of the rolls is virtually entirely supported by the holding devices which engage the ends of the winding core tubes. Consequently, this winding machine is generally unsuitable for producing heavy, wide rolls.
Another type of winding machine for winding an undivided web onto a roll is disclosed in U.S. Pat. No. 3,869,095. This machine has three supporting rollers mounted in a machine frame with their longitudinal axes generally parallel to each other, each two adjacent rollers forming therebetween a respective winding bed. In this machine, the winding beds are used alternately to allow continuous winding to be achieved. This machine is generally not suitable, not desirable, for winding webs, which are slit lengthwise, in a winding bed because there is the possibility that, since the strips are not precisely guided, that the ends of the winding rolls will be crushed against each other and ruined.
The winding machine of the present invention is based on the problem of providing a winding machine in which high quality wound rolls of any length can be efficiently produced automatically.
The winding machine of the present invention includes the advantage wherein the weight of each wound roll is supported by two supporting rollers, namely, the central supporting roller and one of the two outermost supporting rollers. In this manner, each roller is required to support only a fraction of the weight of the roll. Further, the linear pressure on the supporting rollers is kept to a minimum, so that the web on the winding roll is not subjected to any overstressing condition. Moreover, the two supporting rollers provide reliable and stable support for the roll over its entire axial length, thereby preventing the sagging of long winding rolls.
By feeding the web strips into the winding beds from below the winding beds, and using supporting rollers with multiple motor drives, the roll density can be reliably controlled in an easy manner with different amounts of pressure or torque acting on the rollers.
The compact arrangement of the ejection apparatus above the central supporting roller provides a compact machine requiring a minimum amount of space. Furthermore, the winding machine of the present invention provides a process for quickly and automatically changing rolls because of the simultaneous ejection of finished rolls from their respective winding beds, their removal from the machine in conjunction with the inserting device for inserting new core tubes, a severing device that severs the wound web strips, and a device that attaches the new web strips to the new core tubes with an adhesive material. Manual intervention during a roll changing operation is therefore eliminated.
The winding machine of the present invention provides various embodiments in which the three supporting rollers are arranged. In one embodiment, the axes of all three supporting rollers lie in a common plane, which is obliquely inclined relative to the horizontal and viewed in the axial direction. By inclining the common plane of the three supporting rollers, the different distribution of the weight components of the winding rolls on the supporting rollers can be used to vary the roll density. In this embodiment, the outermost supporting roller that is disposed higher than the other two supporting rollers is mounted such that it can be lowered relative to the other supporting rollers to permit its wound roll to be just as easily ejected from its winding bed, as the other roll is from its lower winding bed.
In another embodiment of the winding machine of the present invention, the central supporting roller is disposed with its longitudinal axis above the common center axis plane of the outermost supporting rollers. In this embodiment, with relatively small diameter supporting rollers, sufficient space is created above the central supporting roller for mounting the ejection apparatus or apparatuses. In this case, all three supporting rollers may have approximately the same diameters, however, improved spatial conditions exist above the central supporting roller when the diameter of the central supporting roller is greater than the diameters of the outermost supporting rollers.
In an expedient fashion, it is possible to influence the roll density as the weight of the roll increases by providing the holding assemblies with clamping heads that act on the core tube of the roll, and which are longitudinally movable along the path of the roll axis with adjustable weight-relieving of the roll. However, to achieve a firm initial winding, each roll is provided with a loading device having an adjustable loading roller effective to apply a force or pressure in the direction of the winding bed.
Optimum conditions for saving space and for the efficient operation of the winding machine of the present invention are obtained when the ejection apparatus comprises a beam pivotal around the central supporting roller for each winding bed, and which has mounted on its upper side the core tube insertion device. New core tubes are thus being moved toward respective winding beds when the ejection beams push the finished rolls over their respective outermost supporting rollers.
The insertion device comprises a sliding carriage which is movable along the axial length of the ejection beam when the ejection beam is at its rest position. The sliding carriage is then loaded with new core tubes when it has been moved out of the winding machine. Thus, loading of the carriage can be accomplished at an easily accessible location without affecting the winding process. The insertion device further comprises clamping shoes for holding the core tubes in the correct position on the sliding carriage, thereby preventing their displacement during movement of the carriage. The insertion device does not release the core tubes until the ejection beam is in its working position, at which time they are supplied on guides to the respective holding assemblies and gripped by the clamping heads. To prevent the guides from adversely affecting the rolling process, the guides are formed as rails mounted on respective holding assemblies such that they are extendable upwardly toward the insertion devices, thereby allowing the new core tubes to roll obliquely downwardly to the clamping heads. After a new core tube has been clamped, the guide rails are withdrawn into the holding assemblies.